Protective coating composition

ABSTRACT

A protective coating composition comprising a silicate, such as an organosilicate, an organosilicate polymer and colloidal silica and an organic titanate, preferably a titanate chelate or a titanate ester in a suitable organic solvent. The composition is free from metal particles.

The present invention relates to a protective coating composition forcoating onto metal substrates, particularly metal substrates which havebeen pre-treated with a means of inhibiting corrosion such asgalvanisation or a corrosion inhibiting coating which contains metalparticles such as zinc and optionally aluminum.

Traditionally galvanisation has been the primary means of applying aprotective metallic layer onto a metal substrate. Galvanic layers areoften subsequently passivated or phosphatised as a further means ofprotection against corrosion. Passivation may be defined as the chemicaltreatment of galvanised or stainless steel with a mild oxidant, such asa nitric acid which may facilitate the formation of a thin, transparentoxide film, typically derived from a chromium III or Chromium VIcontaining solution that protects the steel from selective oxidation.Phosphatisation is the treatment of the steel or galvanized steel with aphosphate such as iron phosphate as a means of protecting the steelagainst corrosion. A top-coat may also be applied in the form of alacquer or resin or the like.

One problem with steel substrates treated using the above processes isthat the resulting substrates have poor anti-friction properties and assuch it is often required for such treated substrates to have ananti-friction coating applied on top of the passivation layer. Howeversuch anti-friction layers provide the substrate with little, if any,additional corrosion resistance and may indeed reduce the level ofcorrosion resistance provided by traditional galvanic andpassivation/phosphatised treatments.

Top-coats for galvanized steel are discussed in U.S. Pat. No. 5,393,611and U.S. Pat. No. 5,324,545 both of which relate to a dip-coating methodfor protecting chromatised or passivated galvanic layers on steel or thelike using a composition of a titanic acid ester and a “so-called”organofunctional polysiloxane, preferably having between 2 and 10siloxane repeating units and epoxy end groups. There is no cleardefinition of the meaning of the term organofunctional polysiloxane ineither of these documents but it would seem to mean a polymer with asiloxane backbone having at least one Si-R bond where R is anunsaturated or functionally substituted hydrocarbon radical. Confusinglyhowever the examples in U.S. Pat. No. 5,393,611 and U.S. Pat. No.5,324,545 both teach that rather than an organofunctional polysiloxanebeing used the preferred silicon-containing compound is an epoxy silane,namely gamma glycidoxypropyltrimethoxysilane and there is not theremotest suggestion regarding the use of a silicate.

Corrosion inhibiting coatings for metals which are subjected to extremeweather conditions are well known in the art and generally containcorrosion inhibitors in the form of metal particles, in particular zincand/or aluminum flakes together with a binder. The use of zinc flakes insuch coatings is derived from the fact that in the presence of moisturezinc will oxidize in preference to iron, as it is less electronegative.The presence of aluminum flakes in such compositions is thought toinhibit the rate of oxidation of the zinc flakes. Such coatings arediscussed in the applicant's co-pending application No WO 01/85854, aswell as U.S. Pat. No. 4,218,354, GB 1380748, U.S. Pat. No. 4,098,749 andEP0808883. This type of anti-corrosion coating may also utiliseprotective top-coats which substantially consist of organic resins.

Corrosion inhibiting paints have also been described, for example, GB1499556 which relates to a process for hydrolysing ethyl silicate toform a gellable liquid hydrolysate which was mixed with powders such aspowdered zinc for use in an anti-corrosion paint. The ethyl silicate wasacid hydrolysed and the solvent for the hydrolysis was acetone or analcohol.

Anti-corrosion coatings, which do not necessarily contain metalparticles, include WO9824164, a two component coating material for theproduction of electrically insulating coatings on electrosteel sheets,for solid magnetisable cores in transformers, generators and motors. Thecoating material comprises complexes of formula M (OR)₄, where M iseither titanium or zirconium and R is a linear or branched, saturated orunsaturated 1-20C alkyl groups or chelating groups and a polyester,acrylic, acrylic copolymer, alkyd, phenolic or amino resin containinggroups which are neutralisable or readily dispersible in aqueous media.

U.S. Pat. No. 5,720,902 describes a composition for inhibiting corrosionof low carbon steel and comprises (a) a silicate compound such as aninorganic silicate or a silicon compound containing a hydrolysable grouphaving formula R_(n)SiX₍4-n) where X is a hydrolysable group selectedfrom alkoxy or carboxy groups and n=1−3, (b) a complex fluoro acidcompound, exemplified as a fluorozirconic acid or fluorotitanic acid and(c) a crosslinking agent selected from a variety of complexorganozircomium and organotitanium compounds. DE 3329158 relates to ahardenable reactive resin coating composition containing one or morewater-repellents or moisture-sealing fillers or additives. The additivescan be one or more silanes having alkyl, alkoxy, OC₂H₄OCH₃, C₃H₆SH,alkyl-epoxy or alkylamino, or titanates of the formula R—O—Ti (OR′)₃where R and R′ may be for example alkoxy, acrylic acid, long-chainedcarboxylic acid groups, partly esterified acid groups of phosphoric,pyrophosphoric or phosphorous acid or derivatives thereof in combinationwith a filler such as pigment granulates or platelets of metallic Znand/or Zn phosphate and/or borate, water-proofed kaolin or water-proofedhighly-dispersed silica.

According to the present invention there is provided a protectivecoating composition which comprises a silicate selected from the groupof organic silicates, organic polysilicates or colloidal silica and anorganic titanate in a solvent, which composition is free from metalparticles.

For the avoidance of doubt, it is to be understood that the termsilicate is used to mean a compound which contains substantially no Si—Cbonds, i.e. that carbon linkages to silicon in silicates as described inthis invention are substantially always via an oxygen atom (i.e. anSi—O—C bond).

The protective coating composition in accordance with the presentinvention may provide an alternative protective coating to the oxidecoatings based on chromium III or chromium VI compositions used inpassivation processes or phosphate based coatings based onphosphatisation processes. The avoidance of the need for chromium III orchromium VI containing compositions is particularly preferred in view ofcurrent environmental concerns. It is to be understood that the termzinc alloy when used herein means any appropriate alloy of zinc such aszinc alloys with nickel, manganese and/or iron.

Alternatively the protective coating composition may be utilised as aprotective top-coat on an un-galvanised metal substrate surface having apreviously applied anti-corrosion coating. The use of the protectivecoating composition of the present invention will, for example, reducethe likelihood of flaking of metal particles contained in the previouslyapplied anti-corrosion coating.

Suitable silicates include colloidal silica, organic silicates andorganic polysilicates, with organic silicates and polysilicates beingparticularly preferred. Suitable organic silicates and polysilicatesinclude silicate esters, for example silicate ester monomers (e.g. ethylsilicate), hydrolysate (e.g. silicic ester hydrolysate) althoughsilicate ester polymers are preferred, (e.g. ethyl polysilicate).

Suitable organic titanates include titanate chelates (e.g. titaniumacetylacetonate and triethanolamine titanate) and titanate esters, withthe latter being preferred. Suitable titanate esters include titanateester monomers, for example tetrabutyltitanate, tetraisooctyltitanate,and tetraiospropyltitanate, tetraethyltitanate, tetrapropyltitanates,although titanate ester polymers are preferred (e.g. butylpolytitanate,ethylpolytitanate and propylpolytitanate).

Preferably, the silicate and organic titanate combination, hereafterreferred to as the binder, comprises 30 to 60% by weight more preferably40 to 55% by weight of the silicate, and 40 to 70% by weight and morepreferably 45 to 60% by weight of the organic titanate to a total of100% by weight.

The protective coating composition of the present invention may alsocomprise a metal phosphate as a metal particle free anti-corrosionadditive. The inventors have found that the inclusion of such anadditive enhances the anti-corrosion effect of any form of zinc coatingon the metal substrate. Preferred metal phosphates are zinc phosphates,including modified zinc orthophosphates (e.g. modified zincaluminum-orthophosphatehydrate) and modified zinc polyphosphates (e.g.modified zinc aluminum-polyphosphate hydrate), with the latter beingmost preferred. The metal phosphate may be present in an amount of up to33%, (for example 0.1 to 33%) by weight of the solid content of thecomposition of the present invention (i.e. without the solvent),preferably 5 to 20% by weight.

The protective coating composition of the present invention may furthercomprise a thickener, e.g. silica and/or organic modified clay, in anamount of up to 5% by weight of the solid content of the composition(for example 0.1 to 5% by weight), preferably from 1.5 to 3.5% byweight.

The protective coating composition of the present invention may stillfurther comprise a lubricant, for example a wax, including hydrocarbonwaxes and polytetrafluoroethylene (PTFE) wax, preferably apolyolefin-containing wax (e.g. micronised polypropylene hydrocarbonwax), in an amount of up to 8% by weight of the solid content of thecomposition (for example 0.1 to 8%), preferably from 1.5 to 4.5% byweight.

Suitable solvents for use in the protective coating composition of thepresent invention are well known in the art. Organic solvents aresuitable, including alcohols (e.g. methanol, ethanol, propanol,butanol), ketones (e.g. acetone, methyl ethyl ketone, methyl butylketone, cyclohexanone), esters (e.g. butyl acetate), and mixturesthereof. However, preferred solvents are hydrocarbon solvents, inparticular white spirits, due to their high evaporation rates and lowlevels of aromatic compounds. Particularly preferred white spirits arethose containing C₁₁-C₁₆ normal, iso- and cycloalkanes.

Other components which might be added to the protective coatingcomposition in accordance with the present invention include a colorantsuch as carbon black or a colouring pigment and/or a small amount of anorganic resin such as an acrylic resin.

The protective coating composition of the present invention thuscomprises the binder in a solvent, and preferably one or more of andmost preferably each of a metal phosphate anti-corrosion additive, alubricant, and a thickener. Preferably, the solids content of theprotective coating composition comprises, 54 to 100%, more preferably 65to 90%, by weight of binder, up to 33%, more preferably 5 to 20% byweight of metal phosphate, up to 8%, more preferably 1.5 to 4.5% byweight of lubricant, and up to 4%, more preferably 1.5 to 3.5% by weightthickener.

Preferably the protective coating composition in accordance with theinvention will comprise from 30 to 70%, most preferably 40 to 60% byweight of solvent and from 70 to 30% most preferably 60 to 40% by weightof solids as described above.

The protective coating composition of the present invention can beprepared by mixing its components together in any order usingconventional apparatus, however, a preferred method comprises blendingthe silicate and organic titanate to form a mixture, and where presentseparately mixing the lubricant and/or the anti-corrosion additiveand/or the thickener in an amount of solvent (between 5 and 25% byweight) to form a homogeneous additive slurry. The slurry and themixture are then further mixed together with the remaining solvent.

The protective coating composition of the present invention may beapplied to a surface by any conventional application technique, forexample brushing, dipping, dip-spinning and spraying. Other commonapplication methods include spraying drums, centrifuges, electrostaticor automatic spraying, printing and roller coating. The chosen method ofapplication will depend upon the shape, size, weight and quantity ofitems to be coated. The coating thickness has an influence on the lifeand properties of the protective coating composition, and should in theregion of about 1 to 10 μm, preferably 1 to 6 μm. Once the surface hasbeen coated with the protective coating composition, it is dried toevaporate the solvent and cure the protective coating. The resultingprotective coating layer may be cured by, for example, heating at 200°C. for 10 minutes.

As discussed above the protective coating composition may be applieddirectly on to galvanically deposited zinc or zinc alloy layers and theresulting protective coating negating the need for protective layersbased on chromium III or chromium VI compounds and/or phosphatisation.However, where required, the protective coating composition may beapplied onto such layers.

Metal substrates which are galvanised and then passivated and/orphosphatised have poor anti-friction properties and often require thesubsequent application of a suitable anti-friction coating applied ontop of the passivated and/or phosphatised substrate However suchanti-friction coatings provide the substrate with little additionalcorrosion resistance and may actually reduce the level of corrosionresistance. In a further embodiment of the invention the inventors havefound that application of the protective coating composition inaccordance with the invention onto the substrate prior to application ofone or more layers of an organic anti-friction coating provides theresulting coated substrate with significantly enhanced corrosionresistance. These anti-friction coatings may comprise a non-conductiveorganic or inorganic resin, for example, an epoxy, acrylic orpolyurethane resin and a dry lubricant for example molybdenumdisulphide, graphite or polytetrafluoroethylene (PTFE) in a solventwhich may be aqueous or organic based. Examples of such products includethe Molykote® product range (Dow Coming GmbH, Wiesbaden, Germany) e.g.Molykote® D 708, Molykote® D 106, Molykote® D 3484, and Molykote® 7400.

Alternatively the protective coating composition of the currentinvention may be used as a top-coat for anti-corrosion coatings whichhave previously been applied onto a metal surface. One particularlypreferred combination is for the protective coating composition inaccordance with the present invention to be used as a top-coat for theanti-corrosion coating disclosed in the applicants co-pending patentapplication WO 01/85854 in which there is provided a coating compositioncomprising a binder and a corrosion inhibitor comprising metal particlesin a solvent. The binder comprises a silicate, preferably ethylpolysilicate and an organic titanate, and the corrosion inhibitorcomprises aluminum particles and zinc particles, in particular aluminumflakes and zinc flakes.

Particularly preferred combinations of coating layers include:

-   -   1. 1, 2 or 3 coating layers of the composition in WO 01/85854        followed by 1 to 3 coating layers of the protective coating        composition of the present invention    -   2. 1 to 3 layers of the protective coating composition of the        present invention applied to a galvanized iron or steel        substrate and optionally 1 to 3 layers of an organic        anti-friction coating.

The protective coating composition in accordance with the presentinvention may thus be used to improve high corrosion resistance on bothgalvanic layers and anti-corrosion coatings, and optionally for-lifelubrication with defined and constant coefficient of friction forarticles such as automotive components, for example nuts, bolts andother fasteners, door, bonnet and boot lock parts, hinges, doorstoppers, window guides, seat belt components, brake rotors and drums,and other transportation industry related parts.

Further embodiments of the present invention relate to a substratecoated with the protective coating composition as hereinbefore describedand to a method of coating such a substrate with a protective coatingcomposition as hereinbefore described.

The provision of a protective coating composition in accordance with thepresent invention can increase the level of corrosion protection andoptionally provides “for-life” dry lubrication (i.e. the metal surfaceneeds coating only once during its working life) with a defined andconstant coefficient of friction, whilst being Chromium VI-free and notrequiring expensive components as described in the prior art, forexample, complex fluoro acids such as fluorozirconic and fluorotitanicacids. The provision of such a protective coating composition alsoprovides an attractive appearance to articles coated with the coating.

The present invention will now be illustrated by way of example. Allpercentages are by weight. It should be understood that references towhite rust refer to the formation of a white powder/substance on thecoated substrate surface which is the reaction product of the zincoxidation. Red rust is the result of the oxidation of iron. In steelproducts which are, at least in part, coated with a Zinc metalcontaining layer an observer will first notice the formation of whiterust and once substantially all the available zinc has been oxidized,the formation of red rust will be observed.

EXAMPLE 1

Protective coating compositions in accordance with the present inventionwere prepared by mixing the materials identified below and in Table 1.Table 1 discloses protective coating compositions in accordance with thepresent invention. It will be seen that sample 1 omits theanti-corrosion additive zinc-aluminum phosphate. In each case theprotective coating composition was applied onto bolts previously coatedwith an anti-corrosion coating in accordance with WO 01/85854 (hereafterreferred to as the base coat) which comprised 8% by weight of ethylpolysilicate polymer, 13% polybutyl titanate, 3% aluminum pigment, 33%zinc pigment, 5% zinc-aluminum phosphate, 34% petroleum white spirit, 2%polypropylene wax, 0.6% silica and 0.6% organic modified clay.

The protective coating compositions shown in Table 1 below were preparedas follows:

The polybutyl titanate and ethyl polysilicate were added into a mixingkettle with a dissolver disk for a period of 10 minutes. Simultaneouslya slurry of the silica, clay zinc-aluminum phosphate and when presentPolypropylene wax in a proportion of the Petroleum white spirit (about9% by weight of solvent in sample 2 and about 20% by weight of solventin example 1) was prepared in an Ultra turrax homogeniser. The slurrywas then added into polybutyl titanate and ethyl polysilicate mixtureand the resulting mixture was mixed with the dissolver disk for a periodof 30 minutes at which time the residual amount of solvent was added andthe final mixture was mixed in the presence of the dissolver disk for afurther 10 minutes.

TABLE 1 Sample 1 Sample 2 Components Wt % Wt % Petroleum white spirit47.45 43.61 Polybutyl titanate 24.34 22.38 Ethyl polysilicate 24.3422.38 Silica 1.15 1.06 Organic modified clay 1.00 0.91 zinc-aluminiumphosphate 0.00 8.08 Polypropylene wax 1.72 1.58 complete: 100.00 100.00

EXAMPLE 2 Substrate Pre-Treatment

Steel bolts, 10 mm diameter by 60 mm in length, were pretreated bysandblasting.

EXAMPLE 3 Substrate Coating

The pretreated bolts of Example 2 above were coated with 2 layers of thebase coat. Each base coat layer was applied by dip spinning in acentrifuge, partial curing was carried out after the first layer wasapplied for 10 minutes at 200° C., followed by further dip spinning andfull cure at 200° C. for 13 minutes.

Samples 1 and 2 of the protective coating composition were both appliedin an identical fashion and each layer applied was cured at 200° C. for10 minutes.

EXAMPLE 4 Corrosion Resistance

Salt spray test DIN 50021 was performed on the bolts prepared asdiscussed in Example 3. The results are shown in Table 2 below (averageresults taken from test results for 10 bolts). In each example shown twolayers of the base coat were applied and only the top-coat was varied:

TABLE 2 % of red rust on Coating Time (hours) head of bolt Coating 4.1900 0.0 (No top-coat) Coating 4.2 2000 1.7 (1 layer of sample 1) Coating4.3 2000 0.0 (1 layer of sample 2) Coating 4.4 2000 1.0 (2 layers ofsample 1) Coating 4.5 2000 0.0 (2 layers of sample 2)

The above should be compared with the results provided in Table 2a inwhich the same test was carried out with a commercially availableproduct which comprises zinc and aluminum particles and a bindercomprising a mixture of tetrabutyltitanate and trimethoxyvinylsilaneboth with and without a top-coat. The results of the comparative testare provided in Table 2a. It should be appreciated that, in bothcomparative coatings, 2 layers of the basecoat were utilised. It isunderstood that the comparative top-coat is an organic resin comprisingphenolic and epoxy components which may in addition comprise up to about30% by weight of polytetrafluoroethylene (PTFE). It will be noted thatthe amount of red rust which appears on bolts coated with thecomparative base-coat/comparative top-coat combination is significantlygreater than for coatings comprising only the comparative base-coat.Furthermore, the sets of comparative results shown in Table 2a aresignificantly worse than the results than the results in Table 2.

TABLE 2A Comparative Time % of Red Rust Coatings (hours) on head of boltComparative base coat 240 3.00 (basecoat only) 480 6 Comparative basecoat + top-coat 240 16.0 (1 layer of comp top-coat)

EXAMPLE 5 Lubrication

The coefficient of friction of the coated bolts prepared according toExample 3 on a steel surface was determined using an Erichsen AP 541Bolt Testing Machine. Testing was performed on bolts having beentightened 1 and 3 times and a steel surface. Coatings 5.1, 5.2 and 5.3are equivalent to coatings 4.1, 4.4 and 4.5 in example 4. The resultsare shown in Table 3 below:

TABLE 3 Coeff. of Coating Tightenings friction ±variation 5.1 1 0.1170.005 5.1 3 0.117 0.004 5.2 1 0.122 0.003 5.2 3 0.124 0.004 5.3 1 0.1270.003 5.3 3 0.118 0.003

EXAMPLE 6

In the following examples Zinc-Iron and Zinc-Nickel galvanized steellevers were obtained from Holder of Kirchheim-Teck Germany for use astest pieces. Test pieces which were passivated with a chromium IIIsolution were treated by Holder using their Novatec 100 process andcompositions. The top-coat composition in accordance with presentinvention used was as defined in Sample 2 in Example 1 above and wasapplied in the same way as the method of application used for theprotective coating composition described in Example 3 above. The testpieces coated in accordance with Table 4 below were then tested usingthe salt spray test DIN 50021. Heat aging was carried out by subjectingthe test pieces an elevated temperature, 120° C., for 24 a period ofhours. In every example the presence of a coating in accordance with theinvention resulted in an extended period of time before the onset ofboth white and red rust.

TABLE 4 Time Taken for Surface treatment initial observation galvanic ofrust (Hours) layer passivation Sample 2 white rust red rust ZnFe NoneNone 24 48 ZnFe None Present 48 120 ZnFe None Present (heat aged) 48 120ZnFe Cr III based None 72 120 ZnFe Cr III based present 192 288 ZnFe CrIII based Present (heat aged) 192 288 ZnNi None None 24 120 ZnNi NonePresent 336 600 ZnNi None Present (heat aged) 264 600 ZnNi Cr III basedNone 192 288 ZnNi Cr III based present 696 No red rust ZnNi Cr III basedPresent (heat aged) 912 detected after 1848 hours when test terminated

EXAMPLE 7 Replacement Passivation Layer+Organic Anti-Friction Layer

In the following example a variety of galvanized steel parts, forexample small levers were obtained from Holder of Kirchheim-Teck Germanyand used as test pieces. Test pieces passivated with a chromium msolution have been treated by Holder using their Novatec 100 process andcompositions. The top-coat composition in accordance with presentinvention used was as defined in Sample 2 in Example 1 above and wasapplied in the same way as the method of application used for theprotective coating composition described in Example 3 above. Comparativesamples coated with a phosphatising step instead of a chromium IIIpassivation layer were prepared by dipping a galvanized substrate into asolution of Phosbond W 520 from Wunsch-Chemie and drying at 80° C. TheOrganic anti-friction coatings were applied by dip-spinning and weresubsequently cured as follows:

Molykote ® D708 20 minutes at 200° C. Molykote ® D106 60 minutes at 200°C. Molykote ® D3484 10 minutes at 170° C. Molykote ® 7400 15 minutes at23° C.

The coated products prepared as shown in Table 5 were then tested usingthe salt spray test DIN 50021 as previously described in Example 4 aboveand the results are also provided in Table 5 below.

TABLE 5 Time Taken for initial observation of rust Surface treatment(coverage of 2% galvanic Organic Anti-Friction of surface) (Hours) layerpassivation Coating white rust red rust ZnNi None None 24 228 ZnNi NoneMolykote ® D708 2 120 528 coats ZnNi Cr III based Molykote ® D708 2 120648 coats ZnNi Top-Coat 1 Molykote ® D708 2 192 576 layer coats ZnNiTop-coat 2 Molykote ® D708 2 216 672 layers coats ZnNi Cr III basedMolykote ® D106 24 72 2 coats ZnNi Phosbond W Molykote ® D106 24 72 5202 coats ZnNi Top-coat Molykote ® D106 48 72 1 layer 2 coats ZnNi Cr IIIbased Molykote ® D3484 2 24 72 layers ZnNi Phosbond W Molykote ® D3484 224 72 520 layers ZnNi Top-coat Molykote ® D3484 2 72 144 1 layer layersZnNi Top-coat Molykote ® D3484 2 96 576 2 layers layers ZnNi Cr IIIbased None 24 228 ZnNi Top-coat Molykote ® 7400 48 96 1 layer 2 layersZnNi Top-coat Molykote ® 7400 72 168 2 layers 2 layers

It will be seen from Table 5 that each sample coated with the protectivecoating composition of the present invention instead of a chromium IIIpassivation or phosphatisation layer gave significantly better whiterust and red rust results compared to the prior art, except for thesamples having a Molykote® D106 samples where an improved result wasobserved with respect to white rust appearance.

1. A protective coating composition comprising a silicate selected fromthe group consisting of organic silicates, organic polysilicates andcolloidal silica, a lubricant comprising a wax, and an organic titanatein a solvent, which composition is free from metal particles.
 2. Acomposition in accordance with claim 1 comprising 30 to 60% by weightsilicate, and 40 to 70% by weight organic titanate to a total of 100% byweight of the combined silicate and organic titanate.
 3. A compositionin accordance with claim 1 wherein the silicate is selected from thegroup consisting of colloidal silica, silicate ester monomers, silicateester polymers and silicate ester hydrolysates.
 4. A composition inaccordance with claim 3 wherein the silicate is an alkyl polysilicate.5. A composition in accordance with claim 1 wherein the organic titanateis selected from a titanate chelate and a titanate ester.
 6. Acomposition in accordance with claim 1 which further includes ananti-corrosion additive.
 7. A composition in accordance with claim 6wherein the anti-corrosion additive comprises a metal phosphate.
 8. Acomposition in accordance with claim 1 wherein the wax is selected fromthe group consisting of (i) hydrocarbon waxes and (ii) polytetraethylenewax.
 9. A composition in accordance with claim 1 which further includesa thickener.
 10. A composition in accordance with claim 1 having asolids content comprising from 54 to 90% by weight of the silicate andorganic titanate, up to 33% by weight of a metal phosphate, up to 8% byweight of a lubricant, and up to 4% by weight of a thickener.
 11. Asubstrate having a protective coating formed from up to 3 coatinglayer(s) of a composition in accordance with claim
 1. 12. A substratehaving a protective coating in accordance with claim 11 wherein theprotective coating has been applied on to a galvanically deposited zincor zinc alloy surface.
 13. A substrate in accordance with claim 11wherein an organic anti-friction coating has been applied over theprotective coating.
 14. A substrate having a protective coating inaccordance with claim 11 wherein the protective coating has been appliedon to a surface comprising an anti-corrosion coating.
 15. A substrate inaccordance with claim 11 wherein the substrate is selected from thegroup consisting of nuts, bolts, other fasteners, door, car hood lockingparts, trunk lid locking parts, hinges, door stoppers, window guides,seat belt components, brake rotors, and brake drums.
 16. A compositionin accordance with claim 8 wherein the hydrocarbon wax is apolyolefin-containing wax.